Wrench.



E. H. ROBBINS. WRENCH. APPLICATION FILED AUG. 18, 1912.

Patented Jan. 13, 1914,

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ATTORNEY.

CULUMBIA PLANOGRAPH co. WASHINGTON. u, c.

' State of Massachusetts,

EUGENE H. ROBBINS, OF PITTSFIELD, MASSACHUSETTS.

WRENCH.

Specification of Letters Patent.

Application filed August 13, 1912. Serial No. 714,888.

To all whom it may concern:

Be it known that I, EUGENE I-I. ROBBINS, a citizen of the United States,residing at Pittsfield. in the county of Berkshire and i have inventedcertain new and useful Improvements in Wrenches, of which the followingis a specification.

My present invention relates to wrenches to that class known and, moreparticularly, as chain pipe-wrenches in which a catenation of movablyconnected elements is employed as a clamping member in connection withan actuating arm or lever.

Among the principal advantages of wrenches of this class are thefacility with which they may be adjusted to the work and their superiorgripping powers in operation. The chain conforms itself readily to theoutline of the object to be moved and presents to the engaged surface aplurality of antifrictional contacts which bind without cutting.

The essential objects of the present construct-ion are to increasethegripping power of the device by arranging a relatively greater portionofthe clamping member in engagement with the ob ect, thereby increasingthe number of points of c0ntact, and by removing all angles in the lineof stress exerted through the clamping member.

A further object is to prevent the clamping member from becoming lockedin the holding jaw after use.

The foregoing and other ob ects I accomplish by the provision of aointed GXtEiIISlOIl on the head of the lever which lies in the arc ofthe clamp or chain and removably secures the free end of the chainwithout defleeting it from the surface of the engaged object, the stressor pull exerted by the lever upon the chain being directed through theextension in a line of even curvature substantially coincident with thearc of the chain, thus avoiding the angular deflections common inprevious known forms of devices of this character.

I will proceed to describe a specific useful form of embodiment of myinvention, in connection with the accompanying drawings, wherein- Figure1 is a side elevation of a wrench constructed in accordance with thepreferred form of the invention and operatively mounted upon a pipe;Fig. 2, a sectional top view of the clamping end of the device; Fig.

3, a sectional view of the lever head or shoe in detail, and Figs. 4-and 5, detail views of the extension coupler link and the jaw,respectively.

The lever 1 may be of any usual form, size or material, but ispreferably constructed of wrought metal and is herein shown to comprisethe usual head or holding-shoe 2, having inclined serrated faces 3, 3,and a tapering shank 4, which may be provided at its rear end with aclevis 5 for detachable connection with a tackle or other support. Theserrated faces 3, 3, are curved in outline and preferably constructed ofseparate metal strips, which are welded or otherwise secured to the head2 and suitably tempered for wear, the serrations being relatively smalland adapted to prevent slipping without working injury to the pipe 6 orother ob ect during engagement.

The head 2 is provided with an adjustable extension comprising a couplerformed of separate links 7, 7, arranged in parallel, and a movabletongue 8 having a jaw 9 to receive the free end of the chain 10. Thelinks 7 7, are shown as flat plates curved lengthwise and pivotallysecured at their rear ends to the head 2, preferably at the center lineAA of the lever 1, and extended forward beyond the limits of the head.Pivoted between the front ends of thelinks 7, 7, is the tongue 8, shownas slightly curved on its underside to conform to the convex surface ofthe pipe 6 on which it normally rests and provided at its front end withan lip-turned aw 9 arranged for position in the are of the chain 10.

The clamping means comprises a series of inovably connected orarticulated elements, such as the links 11, 11, etc., of the chain 10,secured to a pivotal support or clevis 12 attached to the lever 1 in therear of the links 7, 7, and extending around the pipe 6 to the 'aw 9.The clevis 12 is preferably arranged as far forward on the head 2 of thelever as practicable in order to enable the chain 10 to engage as muchof the periphery of the pipe 6 as possible.

In adjustment the chain 10 is turned if necessary so that the linkopposite the jaw 9 is inserted edgewise, the chain being held inposition by the engagement of the jaw with the next following link. Torelease the chain from the holding jaw after use the lever 1 is loweredslightly at its rear end. In many previous known forms of devices ofPatented Jan. 13,1914.

, in the plane of the lever this class the holding j aw or securingmeans for the clamping member is arranged as a fixed part on the top ofthe shoe above the center line of the lever and outside of the arc ofthe chain, whereby the chain often becomes tightly wedged after use.

I claim 1. In a wrench, the combination with a lever having a headprovided with a serrated face, of a chain to operate as a clampingmember for engagement with the object to be moved, said chain beingdisposed wholly and secured at one end. thereto in the rear of said headand having a free end, and means for detachably securing the free end ofthe chain to the lever, including extension plates pivotally secured tothe lever beyond the point of attachment of the chain to the lever, anda tongue member pivotally secured to the plates and having a jaw toreceive the chain.

2. A wrench comprising a bar having a head provided with oppositelyarranged serrated faces, an adjustable extension pivot-ally secured tothe center line of the bar and projecting beyond the head, and aflexible looped member secured at one end to the bar in the rear of thehead and having a free end for detachable engagement with saidextension.

In testimony whereof I hereunto aflix my signature in presence of twowitnesses.

EUGENE I-I. ROBBINS.

WVitnesses:

J NO. J. lVHIT'rLEsnY, WILLIAM E. BAGG.

Copies of this patent may be obtained for five cents each, by

addressing the Commissioner of Patents,

Washington, D. O.

